Jtv 69 Battery

It takes 3.5 - 4 hours the first time. It'll go constant red when charging. Pressing the battery test should have shown you something after 3 hours though. You might have a bad battery. Leave it charging overnight and if still nothing the next day, send the battery back.

I would like to hear from rchibnik about what voltage he measured at the terminals of the battery.

The line6 battery measures 7.75 v

The Mavica battery measures 8.30 volts

The line6 battery is on the left. Notice the shape of the pins are different and seem to be larger. The third element on the Mavica battery are larger, but both seem flush with the bottom of the battery.

Turns out I lied. The Variax battery box does contact that third contact on the battery. Not sure what it does. I will try to make some measurements. From the above pix it does look like the contacts are slightly different. Maybe the third element is used differently. (The charger does not contact the third element) I will make some meter measurements on my battery and see if I can see what is on the third element.

OK I measured my Line6 JTV battery. The third terminal is connected to the Negatiave (-) terminal with about 9.5K ohms. It reads 9.5K in both directions so it's probably just a resistor - no diode. My fully charged battery reads about 8.3V (4 LED's on the Variax test button) Maybe rchibnik could compare readings on his Line6 and Mavica battery.

My fully charged Line6 battery measures 8.45v on the two terminals, and 8.35 when I connect the negative to the third terminal

When I do the same thing on the Mavica I get 8.30v on the two terminals, but 0.01v when connecting the negative to the third terminal.

So my conclusion from those observations is that the Mavica lacks the terminal connection with the resistor. Next step would be to dissasemble the battery, followed by a small explosion. Let me get through my gig this afternoon, and we'll see about it tonight. Open to any suggestions.

Did you try to measure resistance between the third terminal and the negative terminal? Thats where I was seeing the 9.5K resistor. The Battery itself is compatable. Same voltage and capacity. Measure voltage between third terminal and negative first. IF it's zero, then try measuring ohms. Don't measure ohms if there is any voltage reading at all between the third terminal and the negative. You can try that on the Line6 battery too. You should see about 9.5K ohms between the negative terminal and the third terminal.

My comment was addressed to 'rchibnik', not you :-). I'd hate to see someone let the magic smoke out of their meter. My Fluke bench unit is quite tolerant of such abuse, but I doubt the low-end units are as well protected.

I am also seeing that quiescent 9.5K reading on the Line6 battery. If UPS ever manages to get my JTV-69 back to me, I'll dig in and try to figure out whether that's really just a simple R between those terminals or, as I more suspect, the port impedence of some sort of crypto based protection system (typical of camcorder packs, toner cartridges, etc.).

Since I don't have another battery to compare I really can't say what is different between the Camcorder battery and the Line6 one. I read it in both polarities to see if there was any sign of something other than a resistor in that circuit. Doesn't seem to be. If I had one of those cheap replacement batteries I would take it apart and see what's in there. I like doing a little reverse engineering from time to time. In the past I have been paid big bucks to do just that. :-)

I am not all that motivated to have a second JTV battery at the moment. I would like to convert my Variax 500 to a better battery though. I am using NIMH AA cells in it.

I have been searching around and one possible use for the third connection is to monitor battery temperature. Many Lithium batteries have an internal temperature sensor. However, I would think this would come into play when charging the battery not when discharging it.

I have been searching around and one possible use for the third connection is to monitor battery temperature. Many Lithium batteries have an internal temperature sensor. However, I would think this would come into play when charging the battery not when discharging it.

I am so glad I started this discussion about less expensive battery alternatives. It is so interesting!! I love forums with smart people as members.

I can't resist tinkering with things. I have searched around but I can't find any kind of battery box that would allow me to adapt my old Variax 500 to a Lithium rechargable. A 7.2V 2500mAH Lithium would run it just fine if I could interface to the battery.

Charlie, I bet you can find a round crimp-on terminal that will make a decent fit in the +/- contacts of the battery. With a little hand tool work, you can probably fix them into a small piece of plexi and whip up your own connector.

I could do that but it would be hard to make anything that would be easy to insert and remove the battery. I would probably hard wire it and make a way to charge it while still in the guitar. I have a bunch of Lithium batteries for my electric model airplanes that have molex connectors on them. That would be an easier route. If I could find a Battery box like the JTV has I would use that but I doubt that anybody sells anything like that.

Line 6 support told me full compass is where I should go for some things.

To add to this discussion (several months later): the pictures of the battery compartment here indicate all 3 contacts are in use, and go to a small PCB that has enough circuitry to indicate the 3rd pin is of strict importance.

FWIW, I played a 500 for many years, and although it was the perfect utility guitar for me, the power issues were a major PITA, so I finally got rid of it in 2014. The battery issue was this; the guitar was only reliable when using good quality carbon AA's but went through them so fast I would unplug the guitar during breaks to preserve them. I got two additional battery cassettes and kept one backup near the stage at all times. In an attempt to save cost i tried NiCAD's, but High MAH NICAD'S didn't have as much starting current when fully charged and lasted maybe an hour. There's nothing quite as frustrating as having the guitar start that damned "blinking on and off" during the solo I waited all night to play. Anyway, those issues have kept me away from the JTV guitars but, to my own amazement, today i will be trading something for a nearly new JTV 59S. I am experiencing guarded excitement about having another Variax, and more than anything else, I hope the battery it uses does become a problem.

The card that came with the charger says that, in the beginning of the charge cycle, the red status light on the charger will be solid red. When the charge cycle is complete it will slowly blink, BUT leave the battery on charge an additional 60 minutes. Then, if you don't remove the battery from the charger, the charger with automatically go into a 20MAH trickle charge. I have tried this and it is correct.